Vacuum impregnating apparatus for treating webs

ABSTRACT

A vacuum impregnating apparatus in which cloth is passed firstly past a vacuum unit which removes air from the cloth interstices. The evacuated cloth immediately being presented to an impregnation unit which delivers impregnating liquid into the evacuated cloth. The impregnated cloth is then subjected either to the action of a squeezing nip or suction unit to remove excess impregnating liquid.

United States Patent [1 1 Farrar 1 1 Oct. 23, 1973 [54] VACUUM IMPREGNATING APPARATUS 1,606,089 11/1926 McConnell 68/l9.1 FOR TREATING WEBS 2,494,807 1/1950 Haeberlin 68/20 X 2,876,063 3/1959 Bond 68/181 R X Inventor: Gervase Bernard F h 2,900,991 8/1959 Arnold.... 68/205 R x chester, Lancashire, England 3,190,793 6/1965 Starke 68/20 X [73] Assignee: Sir James Farmer Norton & C0.,

Limited, Manchester, England J Primary ExaminerJohn Petrakes [22] Filed: Feb. 7, 1972 Assistant Examiner-Philip R. Coe [2]] App No 224 076 Attorney-Richard C. Sughrue et al.

[30] Foreign Application Priority Data [57] ABSTRACT Feb. 10, 1971 Great Britain 4,350/71 A vacuum p g g apparatus in which cloth is 2 l u passed firstly past a vacuum unit which removes air [5 1 U S C 68/19 V E from the cloth interstices. The evacuated cloth imme- [51] Int Cl Bose 5/02 305C 9/08 diately being presented to an impregnation unit which i 68,19 1 22 R delivers impregnating liquid into the evacuated cloth. "g R The impregnated cloth is then subjected either to the action of a squeezing nip or suction unit to remove ex- [56] References Cited cess impregnating liquid.

UNITED STATES PATENTS 4/1890 Stiner 68/19 17 Claims, 12 Drawing Figures VACUUM IMPREGNATING APPARATUS FOR TREATING WEBS such liquids and/or fluids.

Hitherto with conventional methods of impregnation which, for the most part, comprise immersing the web in a tank containing a treating liquid followed by squeezing between a pair of rolls, it has been impossible to obtain the desired complete saturation of the webs by the treating liquid. To assist liquid absorption of pick-up webs have been previously prepared by scourin g to render them absorbent. When webs are not properly or uniformly or leveliy prepared across the width, not only has it been found difficult to force liquor into the web but the degree of absorption of the liquor by the web frequently varies across the width with the result that the appearance of the web is not uniform.

The present invention provides apparatus which increases the absorption of treating liquid and/or fluid into webs and in consequence which obviates or mitigates the need for previous scouring and preparation in many cases, and further which ensures at the same time a perfectly uniform or level saturation and therefore uniform or level effect on the web across its width.

According to the present invention there is provided apparatus for use in the impregnation treatment of a textile or other web with a liquid and/or a fluid, the apparatus comprising a vacuum chamber having a slot or other opening past which a web can be moved, an impregnation bath immediately. after the vacuum chamber, and an impervious, vacuum-sealing belt, band or the like for moving the web past the vacuum slot in close contact therewith and past or'through the impregnating bath. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. l is a diagrammatic vie w of an impregating apparatus according to the present invention;

FIG. 2 is a fragmentary sectional view of a cylindrical screen and its mounting and within which thevacuum chamber and impregnating bath are disposed;

FIG. 3 is a sectional end view of the vacuum chamber and impregnating bath within the cylindrical screen;

FIG. 4 is a plan-view of a wearingmember disposed within the cylindrical screen and providing vacuum slots or openings and impregnating medium outlets;

FIG. 5 is a section on the line VV of FIG. 4;

FIG. 6 is a fragmentary underneath plan view corresponding to FIG. 4;

FIG. 7 is a diagrammatic view of the drive of the apparatus;

FIG. 8 shows an example of an entry and exit arrangement for the apparatus;

FIG. 9 is a diagrammatic view of an apparatus according to the invention when it is to be used with solvent liquors;

FIG. 10 is a diagrammatic view of another modified apparatus;

and,

FIGS. 11 and 12 are a sectional view and a fragmentary underneath plan view of a modified wearing plate.

Reference is made firstly to FIG. 1 of the drawings.

The apparatus comprises basically a cylindrical p0 rous metal screen 20 in which is housed a wetting-out unit consisting of a vacuum box 21 and a liquor box 22 serving as an impregnation unit, and a rubber or other elastomeric endless belt 23 impervious to the treating liquor.

The textile web or cloth which is to be impregnated is indicated at 24.

The web 24 is transported through the wetting-out unit between the porous metal cylinder or band 20 and the rubber belt 23. The web 24vwhich is trapped between the cylinder 20 and the rubber belt 23 passes successively under a vacuum slot and the outlets of the liquor box 22. The web 24 is not subjected to any tension or drag from the suction slot due to the fact that the cylinder 20 and the belt 23 are driven.

It will be manifest that the rubber belt 23 provides an effective seal to obviate or mitigate loss of vacuum.

The suction circuit is indicated by dotted arrows and comprises the vacuum box 21, a high vacuum receiver 25-and a high vacuum pump 26.

The liquor circuit is indicated by full arrows and comprises the liquor box 22, a liquor level trough 27 which, in use, is at the same level as the liquor box 22, a liquor supply tank28 fed from mixing tanks (not shown) and a drip trough 29.-

Pumping traps for the suction and liquor circuits'ar'e indicated at 30.

A'washing circuit is also provided for the apparatus and is indicated by dot-dash arrows. This circuit uses,

say, hot water and serves to wash out the receiver 25, the supply tank 28, the liquid level trough '27 and the liquor box 22 and vacuum box 21.

After impregnation'the web 24 is subjected to means for removing excess liquor. Such extraction means may be eithera squeezing nip 31 or suction extraction. In the lattercase, there is a suction box 32 with an appropriate slot which is connectedto a suction receiver 33 and a suction pump 34. The suction box 32 and receiver 33 are connected to the washing circuit.

In either case excess liquor is returned to the storage tank 28. l v

Any liquor which is drawn into the high vacuum line is trapped -.and pumped'into the storage-tank 28.

The above-described apparatus is a recirculatory. ap-

paratus. Where the apparatusis to be used with liquors:

unsuitable for recirculation, the storage tank 28 is omitted and the liquor level :trough 27 is' f ed directly- .from mixing tanks (not shown). Alsodrains are provided at locations D, the piping between two of these locations and the drip trough 29 and the trough 27 re- I spectively being omitted. v

The wetting-out unit will now be describedin greater detail. I

. The unitcomprises a tube 35 closed at itsbottom a high density polyethylene wearing plate'36 and subdivided internally by a partition 37 to define the vacuum box 21 and the impregnation box 22. The tube 35-is closed at one end by a plate 38 and at its other end abuts -a plate 39'formed with an opening 40.

The plates38 and 39 are secured respectively to stationary tubes 41 and 42 of the machine. Surrounding each tube 41 or 42 is a rotatable annular mounting 43, or 44 there being a bearing 45 between tube 41 and annular mounting 43 and a bearing 46 between tube 42 and annular mounting 44. The annular mountings 43 and 44 have secured thereto the ends of the porous metal cylinder which is constituted of very thin flexible mesh material, for example electrically-deposited pure nickel with a mesh size of, for example, between mesh and 100 mesh. These mesh sizes are nonlimitative as it appears unlikely that the mesh size is critical.

The annular mounting 43 and bearing 45 are position stationary while the annular mounting 44 and bearing 46 are axially movable relative to the tube 42 under the action of springs 47 between the plate 39 and the mounting 46 to ensure tensioning of the cylinder or band 20.

The vacuum circuit is connected to the vacuum box 21 by convenient piping 48 and the liquor circuit is connected to the impregnation box 22 by convenient piping 49.

The wearing plate 36 is most important and is provided with a series of holes 50 for securing it to the tube 35 by bolts or studs (not shown). The impregnation box outlet is constituted by an elongate slot 51. This construction ensures that there is uniform application of the treating liquor to the web or cloth 24 thus avoiding spotting, i.e., non-uniform application of the treating liquor. The suction slot or opening is constituted by two parallel rows of staggered holes 52 with the bottom ends of the holes 52 in each row being connected by an elongate slot 53. The provision of these slots 53 ensure uniform removal of the air from the cloth or web 24 thus avoiding striping on the cloth or web.

The spacing between the vacuum holes 52 and slots 53 and the impregnation slot 51 is small, say between one and two inches and preferably one and a half inches. It is important that this distance be as small as possible to ensure that no air or as little air as possible enters the evacuated interstices of the web of cloth 24 before entry of the treating liquor.

In a modified wearing plate (FIGS. 11 and 12), the impregnation box outlet is constituted by a series of holes 86 communicating with an elongate slot 87, while the vacuum or suction slot is constituted by two parallel rows of staggered holes 88 with the bottom ends of the holes 88 in the row adjacent the vacuum holes 86 being connected by an elongate slot 89. The holes 88 in the other row may also be connected by an elongate slot 90 (shown in phantom line).

It is appropriate to mention here that the impervious endless belt 23 passes round two rollers or drums 55 and 56, the roller or drum 56 being driven as hereinafter described and the roller or drum 55 being mounted so as to apply a tension to thebelt 23. This mounting may conveniently be a pair of arms carrying the roller 55, the arms being pivotal to effect the tensioning. Alternatively, the roller 55 may be mounted on a slide arrangement.

The apparatus drivearrangement is illustrated in FIG. 7 of the drawings. The prime mover is an electric motor 57 with speed reducer 58 whereof the output sprocket 59 drives, via a belt or chain 60, the roller 56. The belt or chain 60 also drives a gearwheel 61 which through a gear train 62 rotates a large-diameter gearwheel 63 fast with the cylindrical screen assembly 20. Guide rolls or sprockets for the belt or chain 60 are indicated at 64.

Various entry and exit arrangements may be used with the apparatus, for example, entry from wagon or batch and exit to plaiter or batch or predryer or other machine.

A convenient but non-limitative entry and exit arrangement is shown in FIG. 8.

The entry arrangement comprises entry rails 65, an entry batch 66, scroll and tracking rolls 67, uncurlers 68, driven openers 69, and cloth guider 70. These entry arrangement components are not all used together but are optional depending on the kind of material being treated.

The exit arrangement comprises a delivery batch 71, a giant batch 72 or a feed 73 to other machines.

In use a web or cloth 24 is fed through the wettingout unit where it is successively evacuated of air and immediately impregnated with treating liquor as aforesaid, excess moisture being thereafter removed by the suction slot or squeezing nip.

This apparatus allows total saturation or liquorlogging of the web or cloth with many advantages, viz: l. Dyeing Levelness and uniformity of shade (in some instances stronger shade than normal padding.) Freedom from skitteriness or frostiness. Complete penetration.

Easy impregnation ofwater-repellent or hydrophobic fibres, e.g., synthetic fibres.

Many unscoured fabrics, especially knitted cottons, can be dyed as well as if they had been scoured. (But it is necessary to confirm that size and impurities do not interfere with the-dyeing or fixation process).

Elimination of the seam line apparent on circular knit goods pad-dyed conventionally.

2. Bleaching. I

By vacuum impregnating the bleach liquor, the same degree of whiteness can be obtained with appreciably less chemical (viz. peroxide) and the reaction time reduced. Vacuum impregnation puts the bleach liquor where it is needed-right in the fibre almost instantaneously.

3. Finishing.

The more uniform and more thorough penetration of resin into the fibres improves crease resistance and other such properties.

If the above-described apparatus is used with solvents, it is additionally provided (see FIG. 9) with hinged covers 74 and a connection 75 to a solvent evaporator. The cloth feed path is indicated at 76 and the porous drum and rubber tively.

An alternative construction of apparatus is diagrammatically shown in FIG. 10 and comprises a vacuum chamber or tube 80 connected to a high vacuum pump (not shown) and having in its wall a vacuum slot 81.

An endless belt 82 in the form of a pervious screen passes around the vacuum chamber 80.

A second endless belt 83 of an impervious nature is located adjacent the vacuum slot 81 with oneof its runs passing partially around the vacuum chamber 80 in the region of the vacuum slot 81. This impervious belt 83 forms with the wallet the vacuum chamber 80 upstream of the vacuum slot 81 in the direction of travel of a web 84 an impregnation treating bath 85, for example, a dye bath, appropriate side walls (not shown) for the bath being provided.

This impervious belt 83 is of relatively substantial proportions and is provided with propelling means, such as described with reference to FIG. 7.

belt at 77 and 78 respec- In use, all air is evacuated from the web 84 by passing it past the vacuum slot 81 in the wall of the chamber which is, in turn, almost completely'evacuated by the high vacuum pump. The web 84 is trapped as it passes past the slot 81 between the two endless belts or bands 82, 83, the impervious belt 83 serving as a seal to prevent loss of vacuum.

After passing the slot 81 and while still evacuated the web 84 is immersed inthe liquid with which-it is desired it should be impregnated. The web 84 from which all air has been evacuated thoroughly absorbs the liquor immediately. It is only necessary thereafter to remove surplus moisture from the web by either passing the web through a pair of conventional squeeze rollers or over a second slot to which suction is applied to withdraw in this case the surplus moisture which has not been absorbed by the fibres of the web. In the event that such a suction device is used for removing the surplus liquor, the surface of the web opposite to the suction slot is open to the air and there is therefore no question of evacuating the web as when passing over the first slot.

The belts need not be endless and the treating bath need not be defined by the vacuum chamber and the impervious belt.

What is claimed is:

1. Apparatus for use in the impregnation treatment of a textile or other web with a liquid and/or a fluid, the apparatus comprising a vacuum chamber having a slot or other opening past which a web can be moved, an impregnation bath immediately after the vacuum chamber, an impervious, vacuum-sealing belt, band or the like for moving the web past the vacuum slot closely adjacent thereto and past or through the impregnating bath, and a porous member disposed immediately adjacent the vacuum chamber and the impregnation bath and between them and the imprevious belt to define with the latter a'path for the web.

2. Apparatus as claimed in claim 1,- in which the impregnation bath has an impregnating medium outlet opening on to the porous member between which and the vacuum sealing belt the web can bemoved in close contact with said outlet by the vacuum sealing belt.

3. Apparatus as claimed in claim 1, in which the porous member is a porous flexible metal cylinder within which is located stationarily in tandem the vacuum chamber and the impregnation bath, whereof the vacuum slot or opening and the impregnation outlet are closely adjacent to' one another.

4. Apparatusas claimed'in claim 3, in which the porous metal cylinder houses internally a tube subdivided internally along the axis of the cylinder by a partition to form the vacuum chamber and the impregnation bath and is closed at its bo ttom by a wearing plate bearin g on the internal surface of the cylinder and constituting the bottom of the vacuum chamber and the impregnation bath, the wearing plate being apertured to provide the vacuum opening and the impregnation outlet.

5. Apparatus as claimed in claim 4, in which the impregnation outlet is defined by an elongate slot.

6. Apparatus as claimed in claim 5, in which the slot connects the tops of a row of holes formed in the wearthe impregnating bath.

ing plate.

7. Apparatus as claimed in claim 4, in which the vacuum opening is defined by two rows of holes in the wearing plate with the holes of one row staggered relative to the holes of the other row and with the bottoms of the holes in one of the rows merging in a elongate slot at their trailing edges in the direction of movement of the web, while the holes in the other row merge in an elongate slot at their leading edges in the direction of movement of the web.

8. Apparatus as claimed in claim 4, in which the wearing plate is formed of high density polyethylene.

9. Apparatus as claimed in claim 3, in which the porous metal cylinder is constituted by thin flexible mesh material and is supported at its ends by annular mounting and bearing assemblies, one of which is position stationary and one of which is axially movable by spring means axially to tension the flexible porous cylinder and prevent sag.

10. Apparatus as claimed in claim 3, in which the vacuum sealing belt extends around an arc of the pro ous cylinder, the belt being endless and passing around a pair of rollers, one of which is movable for tensioning said belt while the other is driven.

11. Apparatus as claimed in claim 10, comprising a prime mover driving the belt roller via an endless belt, which belt also drives the porous cylinder via a gear train.

12. Apparatus as claimed in claim 1, in which the impregnation bath is part of a recirculatory circuit including a liquor supply tank connected to the impregnation bath for feeding liquor to the impregnation bath, a liquor level tank also connected to the impregnation bath to ensure topping up of the latter and a drip through under the impregnation bath and vacuum sealing belt to collect excess liquor, the impregnating liquor being fed gravitationally out of the impregnation bath.

13. Apparatus as claimed in claim 1, in which the vacuum chamber is connected to a high vacuum pump via a high vacuum receiver.

14. Apparatus as claimed in claim 1, and further comprising, after the impregnation bath, a squeezing nip to remove excess liquor from the web.

15. Apparatus as claimed in claim l and furthercornprising, after the impregnation bath, a suction pump connected to a suction box via a suction receiver, which further apparatus serves to remove excess liquor from the web. I I

16. Apparatus as claimed in claim 1 in which, when the apparatus is used with solvents, the vacuum-sealing belt, porous member, vacuum chamber, and impregnation bath are enclosed in a casing closed by hinged covers, and the casing is connected to a solvent extractor.

17. Apparatus as claimed in claim 1 in which the vacuum chamber is a vacuum tube with a vacuum slot, the porous member is a driven endless pervious beltsurrounding the vacuum tube, and the impervious belt arcs around the vacuum tube in the region of the vacuum slotand defines with the wall of the vacuum tube 

1. Apparatus for use in the impregnation treatment of a textile or other web with a fluid, the apparatus comprising a vacuum chamber having a slot or other opening past which a web can be moved, an impregnation bath immediately after the vacuum chamber, an impervious, vacuum-sealing belt, band or the like for moving the web past the vacuum slot closely adjacent thereto and past or through the impregnating bath, and a porous member disposed immediately adjacent the vacuum chamber and the impregnation bath and between them and the impervious belt to define with the latter a path for the web.
 2. Apparatus as claimed in claim 1, in whiCh the impregnation bath has an impregnating medium outlet opening on to the porous member between which and the vacuum sealing belt the web can be moved in close contact with said outlet by the vacuum-sealing belt.
 3. Apparatus as claimed in claim 1, in which the porous member is a porous flexible metal cylinder within which is located stationarily in tandem the vacuum chamber and the impregnation bath, whereof the vacuum slot or opening and the impregnation outlet are closely adjacent to one another.
 4. Apparatus as claimed in claim 3, in which the porous metal cylinder houses internally a tube subdivided internally along the axis of the cylinder by a partition to form the vacuum chamber and the impregnation bath and is closed at its bottom by a wearing plate bearing on the internal surface of the cylinder and constituting the bottom of the vacuum chamber and the impregnation bath, the wearing plate being apertured to provide the vacuum opening and the impregnation outlet.
 5. Apparatus as claimed in claim 4, in which the impregnation outlet is defined by an elongate slot.
 6. Apparatus as claimed in claim 5, in which the slot connects the tops of a row of holes formed in the wearing plate.
 7. Apparatus as claimed in claim 4, in which the vacuum opening is defined by two rows of holes in the wearing plate with the holes of one row staggered relative to the holes of the other row and with the bottoms of the holes in one of the rows merging in a elongate slot at their trailing edges in the direction of movement of the web, while the holes in the other row merge in an elongate slot at their leading edges in the direction of movement of the web.
 8. Apparatus as claimed in claim 4, in which the wearing plate is formed of high density polyethylene.
 9. Apparatus as claimed in claim 3, in which the porous metal cylinder is constituted by thin flexible mesh material and is supported at its ends by annular mounting and bearing assemblies, one of which is position stationary and one of which is axially movable by spring means axially to tension the flexible porous cylinder and prevent sag.
 10. Apparatus as claimed in claim 3, in which the vacuum sealing belt extends around an arc of the porous cylinder, the belt being endless and passing around a pair of rollers, one of which is movable for tensioning said belt while the other is driven.
 11. Apparatus as claimed in claim 10, comprising a prime mover driving the belt roller via an endless belt, which belt also drives the porous cylinder via a gear train.
 12. Apparatus as claimed in claim 1, in which the impregnation bath is part of a recirculatory circuit including a liquor supply tank connected to the impregnation bath for feeding liquor to the impregnation bath, a liquor level tank also connected to the impregnation bath to ensure topping up of the latter and a drip through under the impregnation bath and vacuum sealing belt to collect excess liquor, the impregnating liquor being fed gravitationally out of the impregnation bath.
 13. Apparatus as claimed in claim 1, in which the vacuum chamber is connected to a high vacuum pump via a high vacuum receiver.
 14. Apparatus as claimed in claim 1, and further comprising, after the impregnation bath, a squeezing nip to remove excess liquor from the web.
 15. Apparatus as claimed in claim 1, and further comprising, after the impregnation bath, a suction pump connected to a suction box via a suction receiver, which further apparatus serves to remove excess liquor from the web.
 16. Apparatus as claimed in claim 1 in which, when the apparatus is used with solvents, the vacuum-sealing belt, porous member, vacuum chamber, and impregnation bath are enclosed in a casing closed by hinged covers, and the casing is connected to a solvent extractor.
 17. Apparatus as claimed in claim 1 in which the vacuum chamber is a vacuum tube with a vacuum slot, the porous member is a driven endless pervious belt surrounding the vacuum tube, and the impervious belt arcs arouNd the vacuum tube in the region of the vacuum slot and defines with the wall of the vacuum tube the impregnating bath. 